Put kitty litter on the spot. It will help with the smell~!
As silly as it sounds - tomato juice. Let it set for about an hour, and hose off lightly. The acid neutralizes the odor.
The gasoline then with boiling hot water and washing up liquid scrub the floor rinse with boiling hot water and washing up liquid scrub the surface with cold water then put sawdust on top this should lift out the surface with cold water then put.
I have found doing nothing works about as well as anything. Gasoline components are fairly volatile and will all evaporate in time.